The present invention relates generally to handheld printing devices and more specifically to handheld printing devices having xe2x80x9cnavigationxe2x80x9d systems for determining the position of the handheld printing device with respect to the printable object.
Handheld or portable optical scanners are well known in the prior art and are designed to be moved by hand across the object or document being scanned. The handheld scanner may store the scanned image within its own memory or may be connected directly to a separate computer by a data cable which is used to store the scanned image. For example, U.S. Pat. No. 5,381,020 of Kochis, et al., for xe2x80x9cHand-held Optical Scanner With Onboard Battery Recharging Assemblyxe2x80x9d discloses a hand-held optical scanner which comprises a hand-displaceable scanner housing; scanner electrical components mounted within the housing for performing scanner operating functions; a battery disposed in the housing and electrically connected to the electrical components; a generator disposed in the housing and operatively associated with the battery; and a roller assembly mounted in the housing and drivingly linked to the generator. U.S. Pat. No. 5,306,908 of McConica, et al., for xe2x80x9cManually Operated Hand-held Optical Scanner With Tactile Speed Control Assemblyxe2x80x9d describes a hand-held optical scanner comprising an optical sensor for generating a data signal representative of a scanned object; a housing for hand-displaceably supporting the optical sensor; a roller mounted on the housing for enabling rolling displacement of the housing over a scanned object in a predetermined scan direction; a displacement sensing device for sensing the angular displacement of the roller and generating a displacement signal representative thereof; a motor drivingly linked to the roller for applying a driving torque thereto; a controller for actuating the motor responsive to the displacement signal for angularly accelerating and decelerating the roller for urging an operator to hand displace the housing across a scanned object within a predetermined speed range which is optimal for scanning.
Additionally, U.S. Pat. No. 6,002,124 of Bohn, et al., for xe2x80x9cPortable Image Scanner With Optical Position Sensorxe2x80x9d discloses an imaging device which may be comprise of an image head having an elongate slot therein with first and second lengthwise ends. The image head may also include a first navigation sensor aperture and a second navigation sensor aperture positioned adjacent the elongate slot at positions other than positions that are aligned with the first and second lengthwise ends of the elongate slot. An image sensing system optically aligned with the elongate slot in the image head is responsive to image light passing through the elongate slot and produces an image signal based on the image light. A first navigation sensor optically aligned with the first navigation sensor aperture in the image head is responsive to first navigation light passing through the first navigation sensor aperture and produces a first navigation data signal based on the first navigation light. A second navigation sensor optically aligned with the second navigation sensor aperture in the image head is responsive to second navigation light passing through the second navigation sensor aperture and produces a second navigation data signal based on the second navigation light. U.S. Pat. No. 6,005,681 of Pollard for xe2x80x9cImage Scanning Device and Methodxe2x80x9d describes a method of reconstructing an image from scanned parts of an original image obtained by relative movement between a scanning device and the original image so that adjacent scanned image swaths overlap. The scanning device comprises navigation means for determining the position of the scanning device relative to the original image. Navigation corrections are calculated by correlating features within the area of overlap between adjacent swaths.
Also related is U.S. Pat. No. 5,552,597 of McConica for xe2x80x9cHand-held Scanner Having Adjustable Light Padxe2x80x9d discloses a lens assembly which is positioned between an illuminated scanning area and a detector. Positioned between the lens assembly and the illuminated scanning area is a multiple reflecting assembly which defines a folded light path between the lens assembly and the illuminated scanning area. A prismic reflecting assembly is movably mounted between the lens assembly and the multiple reflecting assembly, so that the length and direction of the folded light path can be changed by moving the prismic reflecting assembly to align and focus the image of the illuminated scanning area on the surface of the detector. U.S. Pat. No. 5,586,212 of McConica, et.al., for xe2x80x9cOptical Wave Guide for Hand-held Scannerxe2x80x9d describes first and second elongate curved reflecting surfaces which are positioned in non-parallel, spaced apart relation, which collect light from an elongate light source and direct the light onto a scanning area. One edge of the first curved reflecting surface is positioned adjacent the light source and the opposite edge is positioned adjacent the illuminated scan area so that the first curved reflecting surface extends from about the light source to about the illuminated scan area. The second curved reflecting surface is positioned in opposed spaced-apart non-parallel relation to the first curved reflecting surface such that the distance separating the reflecting surfaces at the light source is less than the distance separating the reflecting surfaces at the end adjacent the illuminated scanning area. An elongate planar reflecting surface is positioned adjacent the second curved reflecting surface so that it is substantially perpendicular to the illuminated scan area. Some of the light rays from the light source are reflected by the first curved reflecting surface and the second curved reflecting surface onto the planar reflecting surface, which in turn reflects the light rays onto the illuminated scan area so that they are incident on the illuminated scan area at substantially oblique angles. Other light rays from the light source are directly reflected by either the first curved reflecting surface, the second curved reflecting surface, or by a combination of the two, onto the illuminated scan area so that they are also incident on the illuminated scan area at substantially oblique angles.
Each of the above described patents are assigned to the assignee of the present application and are hereby incorporated in their entirety by reference for all that they disclose.
Similarly, portable computer printers are well known in the prior art and include dot matrix printers, piezo-electric inkjet printers, laser printers and thermal inkjet printers. Additionally, scanner/printer combinations are known in the prior art as are combination machines which include scanner features, printer features, facsimile machines, and document copying capabilities. However, the scanners used in these combinations are relatively large desktop units serving to optically scan sheet documents transported through or placed on a scan window of the device.
A need exists for a portable printer that is adaptable to print in combination with a portable device on a desktop unit. A further need exists for a compact printer compatible with a handheld device such as a personal digital assistant (PDA).
The present invention describes a system and method of printing an image onto a page with a handheld printer. A page is defined to be the print receiving media or object as including paper sheets, cartons, printable object or media or any other surface capable of receiving an ink, dye, or other material to be applied to a surface. The method comprises the steps of moving a handheld printhead over the surface of a page; locating a position of the printhead relative to the page; and printing a corresponding portion of the image onto a corresponding portion of a print receiving page in response to continuously updated determinations of the location of the printer relative to the page and previously printed portions of the image. A manual movement of the handheld printhead is performed using a series of continuous motions. The location of the printhead may be continuously or near continuously determined with respect to a corner or an edge of the page and/or may use the inherent structural features of the page to detect direction and degree of movement. The determination of the handheld printhead""s position may also use visible or microscopic servo marks formed on the page. The image printed on the page may be stored in a memory of the handheld printer in a bit-mapped representation, printable format, or other acceptable format. The image may also be optically scanned into the handheld printhead in a digital representation of the image. If the image is scanned into the handheld printhead, the scanning may include reading a first swath of the image; reading a second swath of the image; and stitching the first swath with the second swath to produce the image.
According to another embodiment of the invention, a handheld device includes a printhead for printing a facsimile of an image onto a page. The device includes a navigation sensor which determines a position of the printhead relative to the page. A controller correlates the image information with the navigation information from the navigation sensor so that the printhead responds to the image information to print a facsimile of the image onto the surface of the page. The navigation sensor may determine the position of the handheld device from the inherent structural features (e.g., fibers contained in a paper, etc.) and/or with respect to an edge or a corner of the page and/or may use servo marks to calculate its position. The handheld device may also use printed information on the page to determine its position. A memory stores the image data. An optical scanner may be included to capture a representation of the image from an image source such as a printed media.
According to another embodiment of the invention, a handheld device includes an image detector used to scan an image and a printhead for printing a facsimile of the image onto a page. The handheld device includes at least one navigation sensor used to determine a position of the handheld device relative to the surface of the page to provide navigation information. A scanner is used to scan the image from an image source to provide image information. A controller is configured to correlate the navigation information with the image information. A printhead is then included to transfer a facsimile of the image onto the surface of the page. The handheld device may include a memory which stores and maintains links between the navigation information and the image information. The navigation sensor may determine the position of the handheld device from and relative to an edge of the surface of the page, from information printed on the surface of the page, or from a combination of these reference points and methods. The scanner included in the handheld device may provide the image information in elongated, substantially rectangular xe2x80x9cswathsxe2x80x9d that are stitched together to form a complete image. The printhead of the handheld device may also write servo marks on the surface of the page to help keep track of its motion over featureless portions of the media (e.g. blank portions of page).
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.